Still the best but for how much longer?

Surrounded by members of their team, Red Bull drivers Sebastian Vettel of Germany, center row, center left, and Mark Webber of Australia, center row, center right, hold trophies as they celebrate at the end of the Brazilian Formula One Grand Prix at the Interlagos race track in Sao Paulo, Brazil. Webber won the race and Vettel finished second place. AP Photo/Andre Penner

Formula One's paddock army were bleary-eyed on Monday after the end-of-season celebrations following yet another Red Bull triumph in the Brazilian Grand Prix.

But as they packed and prepared for their final homeward flights of a memorable if predictable 2011 season, there were signals that the double champions may not have it all their own way again next year.

Rivals counting on power of continuity

McLaren, with an unchanged line-up and bristling with determination, marched out of Interlagos with nothing less than a bid to end the Red Bull domination on their minds.

Ferrari, also unchanged for 2012, issued much the same kind of confidence in their own future and, with Mercedes improving rapidly and few changes to the technical regulations, a much more competitive season appeared to be in prospect.

All of the top teams and their drivers will be doing their utmost to stop German Sebastian Vettel, 24, and his Red Bull team from completing a hat-trick of title triumphs in both the drivers' and constructors' championships.

McLaren adamant things can change

McLaren team chief Martin Whitmarsh captured the defiant mood when he said: "Red Bull have done a very good job in terms of performance and reliability, but it can change. We want to make sure of that if we can.

“We've been there. We've had back-to-back world championships and then lost form, so we have to attack and go for it. We need to be on the pace right from the opening day."

He said that early feedback from his engineers suggested that McLaren were making encouraging progress with the design of next season's car.

“I sat in the project review meeting last week and we had made some really good progress -- so I came out of it really feeling good," he said. “I think we had a shocking winter last year, probably one of the worst we have had.

“We were nowhere near competitive and had not done a race distance before we finished the Australian race. I am sure we have learned from that."

The consistency of an unchanged driver line-up will be a boost for McLaren, Ferrari and champions Red Bull with Mercedes also unchanged ahead of the 63rd F1 season.